<!DOCTYPE html>
<html>
    <head lang="en">
        <meta charset="UTF-8">
        <TITLE></TITLE>
    </head>
   <body>
       <form action="http://www.w3school.com.cn/js/index.asp">
    <input type=" text"  required="required">
    <button type="submit">提交</button>
    </form>
   </body>
</html>